Accession Number : AD0606071

Title :   DETERMINATION OF THE EFFECTS OF CHEMICAL AND VIBRATIONAL RELAXATION ON AN INVISCID HYPERSONIC FLOW FIELD,

Corporate Author : AVCO CORP WILMINGTON MASS RESEARCH AND ADVANCED DEVELOPMENT DIV

Personal Author(s) : Wood,A. D. ; Springfield,J. F. ; Pallone,A. J.

Report Date : 22 JAN 1964

Pagination or Media Count : 64

Abstract : The conservation equations for an inviscid, nonconducting fluid with chemical and vibrational relaxation are put into characteristic form for the determination of hypersonic flow fields. Application of the analysis to the simpler case of vibrational equilibrium is also discussed. The pressure and flow angle are calculated by local application of these relations, assuming proper values of the speed of sound based on the local composition of the relaxing gas. A coupled nonequilibrium calculation is carried out simultaneously along the streamline characteristic in which the rate equations for individual species production and vibrational relaxation, together with the energy equation, are used to obtain translational and vibrational temperatures and species concentrations, thereby completely determining the state of the gas. Results at typical entry conditions in the Earth's atmosphere are presented for pointed bodies with and without vibrational equilibrium and for blunted bodies with vibrational equilibrium. Comparisons are made with results from frozen and equilibrium analyses. The effects of both chemical and vibrational relaxation, and variation of nose bluntness, on the downstream composition of the gas are shown to be appreciable. (Author)

Descriptors :   (*HYPERSONIC FLOW, NUMERICAL ANALYSIS), GAS FLOW, VIBRATION, FROZEN EQUILIBRIUM FLOW, ATMOSPHERE ENTRY, TEMPERATURE, EQUATIONS, BLUNT BODIES, CHEMICAL PROPERTIES

Distribution Statement : APPROVED FOR PUBLIC RELEASE